<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title></title>
</head>
<body>
	<script>
		var str = '123455'
		var reg = /[a-z]/i;
		console.log(reg)
		var res = reg.test(str)
		console.log(res)

	</script>
</body>
</html>